public void TestSimple()
        {
            var expected = new int[] { 20, 37, 21 };

            var actual = DeleteOccurrencesElement.DeleteNth(new int[] { 20, 37, 20, 21 }, 1);

            CollectionAssert.AreEqual(expected, actual);
        }
        public void TestSimple2()
        {
            var expected = new int[] { 1, 1, 3, 3, 7, 2, 2, 2 };

            var actual = DeleteOccurrencesElement.DeleteNth(new int[] { 1, 1, 3, 3, 7, 2, 2, 2, 2 }, 3);

            CollectionAssert.AreEqual(expected, actual);
        }